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Bioplastics: a clean alternative?

Agricultural films: bioplastics at the farm

Case study Richard Robert, Journalist and Author
On November 17th, 2020 |
2 mins reading time
Agricultural films: bioplastics at the farm
Key takeaways
  • Every year, global agriculture uses 6.12 million tons of plastic, including agricultural films.
  • A few years ago, farmers started using oxo-degradable plastics, which break down when exposed to UV rays, heat and oxygen.
  • 90% of metabolites from these types of films are absorbed by micro-organisms, but that still leaves 10%.
  • Therefore, new regulations will prevent use of oxo-degradable films in Europe from 2021 onwards, leaving biodegradable films in a favourable position to become the alternative.

Inten­sive farm­ing uses more and more plas­tic. On the one hand, this helps reduce envi­ron­men­tal impact, as it means less water con­sump­tion and more pro­tec­tion for crops. But what hap­pens to these plas­tics after they are used? Recent shifts in this area involve a rise in the use of biodegrad­able films as a solution.

Glob­al agri­cul­ture uses 6.12 mil­lion tons of plas­tics annu­al­ly; only a frac­tion of total plas­tic pro­duc­tion. The agri­cul­tur­al indus­try in France, for exam­ple, uses around 105,000 tons of plas­tic every year, which is less than 2% of nation­al con­sump­tion. The fig­ures are sim­i­lar in oth­er devel­oped countries.

Nev­er­the­less, this 2% requires par­tic­u­lar attention.

First of all, for their impact: these films are pri­mar­i­ly used to pro­tect crops in green­hous­es, as anti-hail pro­tec­tive net­ting, ground pro­tec­tion for veg­etable farm­ing or tar­pau­lins for feed pack­ag­ing. In doing so, they help to reduce water con­sump­tion and pes­ti­cide use, con­tribut­ing to an over­all low­er envi­ron­men­tal footprint.

Sec­ond, because of what hap­pens to them after being used. In Europe and the Unit­ed States, there are recy­cling chan­nels for agri­cul­tur­al plas­tics. His­tor­i­cal­ly, how­ev­er, most of these prod­ucts have been shipped to Chi­na, which meant that when Chi­na sud­den­ly stopped import­ing waste for recy­cling in 2018, it blocked up the plas­tic recy­cling chan­nel in the short and medi­um term 1. What’s more, recy­cling is actu­al­ly not the best option for films that are used on farms. They often get dirty and there­fore weigh more, mak­ing them more expen­sive to recy­cle and still pieces of plas­tic are often left behind in the fields. Not to men­tion that recy­cling is vir­tu­al­ly non-exis­tent in many countries.

As such, degrad­able films, which are left to break down in fields after being used, were devel­oped. But whether this process is tru­ly envi­ron­men­tal­ly-friend­ly has been a top­ic of great debate in Europe and the Unit­ed States for the past ten years 2.

Oxo-degrad­able or biodegradable?

For many years, the indus­try has focused on “oxo-degrad­able plas­tics,” a sec­tor led by UK-based Sym­pho­ny Envi­ron­men­tal and Brazil­ian com­pa­ny Tekplast.

These plas­tics are made from poly­eth­yl­ene with a cat­a­lyst to stim­u­late break­down – iron, man­ganese or cobalt sul­phate. When exposed to UV rays, heat, and oxy­gen in the air, the long chains of poly­eth­yl­ene break and oxi­dise, turn­ing into small­er mol­e­cules;  a process that takes between 2–24 months. Man­u­fac­tur­ers assert that 90% of these microplas­tics are then absorbed by microor­gan­isms that live in the soil. How­ev­er, envi­ron­men­tal­ists as well as Euro­pean Bio­plas­tics, the lob­by for bio­plas­tics man­u­fac­tur­ers, are con­cerned about the remain­ing 10% and the pol­lu­tion caused by these microplas­tics, which do not break down even in indus­tri­al com­post facil­i­ties. In 2018, the Euro­pean Com­mis­sion was per­suad­ed by their argu­ments 3.

With an EU ban on oxo-biodegrad­able plas­tics sched­uled for 2021, biodegrad­able films are a favourable alter­na­tive. This up-and-com­ing sec­tor is led by Ital­ian com­pa­ny Novamont. 

When a prod­uct biode­grades, it does not sim­ply break up under chem­i­cal process­es; rather, it is digest­ed by microor­gan­isms. The com­po­si­tion of biodegrad­able agri­cul­tur­al plas­tics dif­fers great­ly, and they are made using spe­cialised tech­nol­o­gy. No less than 50 patents pro­tect Novamont’s flag­ship prod­uct, Mater-Bi.

161,000 tons of biodegrad­able plas­tics are pro­duced for agri­cul­ture world­wide annu­al­ly, five times less than equiv­a­lent prod­ucts in the food pack­ag­ing indus­try 4. Cur­rent­ly, this is a niche with­in a niche. But growth of this emerg­ing indus­try is dri­ven by pres­sure from the recy­cling indus­try and ele­vat­ed EU stan­dards. It is now a Euro­pean spe­cial­i­ty, sup­port­ed by the con­sor­tium Agro­biofilm 5. As the num­ber-one glob­al pro­duc­er by vol­ume, Chi­na is fol­low­ing devel­op­ments close­ly, with leader Pujing Chem­i­cal Indus­try Co. sup­port­ing the work of Euro­pean manufacturers.